1. Field of the Invention
The present invention relates to a pattern forming body which can be used for a color filter or the like used for a color liquid crystal display.
2. Description of the Related Art
Recently, accompanied by development of the personal computers, in particular, development of the portable personal computers, demand to the liquid crystal displays, particularly color liquid crystal displays tends to be increasing. However, since the color liquid crystal displays are expensive, cost down is highly requested. In particular, cost down to the color filters, which accounts for a large proportion in terms of the cost, is highly requested.
In general, such a color filter comprises coloring patterns of the three primary colors including red (R), green (G) and blue (B). The liquid crystal functions as a shutter by switching electrodes corresponding each pixel of R, G, and B on or off, thereby light pass through each pixel of R, G, and B so that the color display is carried out.
As the methods for manufacturing a color filter conventionally executed, for example, a dying method can be presented. In the dying method, a colored pattern is obtained by first forming a water soluble polymer material, as the dying material, on a glass substrate, patterning the same into a desired shape by a photolithography process, and then soaking the obtained pattern in a dye bath. By repeating the same for three times, R, G, and B color filter layers are formed.
Moreover, as another method, a pigment dispersion method can be presented. In the method, a single color pattern is obtained by first forming a pigment dispersed photo sensitive resin layer on a substrate, and patterning the same. By repeating this process for three times, R, G, and B coloring layers are formed.
As still another method, an electro deposition method, a method of dispersing a pigment in a thermosetting resin, printing three times for R, G, and B, and thermally curing the resin, or the like can be presented.
However, in any method, the same process should be repeated for three times for coloring the three colors of R, G, and B, a problem of a high cost, and a problem of the yield deterioration due to the process repetition are involved.
As a method for manufacturing a color filter which can solve the above mentioned problem, a method for forming a coloring layer, in which coloring inks are sprayed by an ink jet method, is proposed (Japanese Patent Application Laid Open (JP-A) No. 59-75205). In the reference, methods to help an ink to fix are disclosed. That is, when an ink having a good wettability to a glass substrate is used, bounding convex parts are preliminarily printed with a material having a poor wettability to an ink, and when an ink having a poor wettability to a glass is used, a pattern is preliminarily formed with a material having a good wettability to the ink.
Moreover, as another method for manufacturing a color filter by forming coloring layers by discharging coloring ink by the ink jet method, a method in which a concave part is treated with a lyophilic treating agent is reported (JP-A No. 9-203803). In this method, convex part is preliminarily formed on a substrate. After making the convex part liquid repellent, the entier surface of the substrate is treated with the lyophilic treating agent.
Furthermore, still another method for manufacturing a colot filter by forming coloring layers by discharging coloring ink by the ink jet method, a method which uses a wettability variable layer utilizing a photocatalyst reaction is proposed by the present inventors (Japanese Patent No. 3381146). In this method a photocatalyst containing layer comprising a photocatalyst is formed on a transparent base material with light shielding part formed, and on the photocatalyst containing layer, a property variable layer, whose property is varied by a function of a photocatalyst due to an energy irradiation, is formed. After that, a property-varied pattern is formed by irradiating the property variable layer, thus providing a coloring layer to the property varied parts. By this method, it is possible to form a coloring layer easily by utilizing the property of the wettability variable layer.
However, in this method, there is a problem of inducing a crack in the photocatalyst containing layer, due to a difference in thermal expansion rate, when the photocatalyst containing layer is formed because the photocatalyst containing layer is formed on the light shielding part. Moreover, there is a problem that an alignment of a liquid crystal may be influenced by a conductivity of the photocatalyst containing layer, when an electrode layer is provided on the color filter, since the thickness of the property variable layer is thin.